Sealed vessels



March 17, 1970 R. RoAcH 3,501,175

SEALED VESSELS Original Filed Sept. 24, 1957 2 Sheets-Sheet 2 PERT LEEROAC'I'/ United States Patent O 3,501,175 SEALED VESSELS Robert LeeRoach, West Chester, Pa., assignor to West Chester Chemical Company,West Chester, Pa., a partnership Application Sept. 24, 1957, Sel'. N0.685,784, which is a division of application Ser. No. 115,099, June 6,1961, now Patent No. 3,272,894, dated Sept. 13, 1966. Divided and thisapplication Sept. 8, 1966, Ser. No. 577,954

Int. Cl. F161 13/00 U.S. Cl. 285-295 15 Claims ABSTRACT OF THEDISCLOSUREv A vessel and a joint which is sealed against gas escapingtherefrom by means of a cured cationic neoprene latex sealantcomposition of a specific type which adheres to and coats the interiorwall of said vessel or joint and plugs their interstices, fissures orother structural defects.

My invention relates to sealed vessels. This application is a divisionof application Ser. No. 115,099, filed June 6, 1961 no'w U.S. Patent No.3,272,894, which itself is a division of application Ser. No. 685,784filed Sept. 24, 1957, and now abandoned.

In the use of underground conduits, as for instance those consisting ofpipelines comprising bell and spigot joints, serious problems havearisen, particularly in instances where the conduit is used forconveying illuminating gas. In communities Where such conduits were laidfor manufactured illuminating gas, it has been customary for the belland spigot joints to be packed with caulked jute or other fibrousmaterials, and the outside of the joint itself caulked. The water vaporcontent of manufactured gas was sufficient to keep the jute in aswoll'enstate and thereby maintain the joint in-fully packed condition. Incommunities of this kind, where manufactured gas was replaced by naturalgas, it was discovered that instead of retaining the moisture in thejute packing, the flow of dry natural gas aspirated the moisture out ofthe jute packing, thereby effecting a shrinkage' of the jute. This inmany instances resulted in the formation of leaks in the bell and spigotjoints. Moreover, such pipe lines were, as a rule, laid in the bed ofstreets and are subject to the stresses of forces transmitted to them bythe pounding and vibration of vehicular traffic on said streets, or bysettling of the pipe due to undermining or other causes. `So long as thejute remained charged with moisture, the packing was sufficientlyresilient to yield to these forces without relinquishing its packingpressure. But when the jute was dried out, it lost its internal pressure'which forced the packing fibers into resilient contact one withanother, and against the walls of the bell and spigot joint or lthecaulking thereof. Instead, said pounding and vibration or settlingforces not only tend to maneuver the dry jute loose from said walls orcaulking, but also tend to separate the dry fibers of the jute, one fromanother. Thus the tendency toward leakage is further enhanced.

Hitherto, such leaks iwere corrected either by removing the pavement andexperimentally digging down to the pipe in an effort first to locate theleak and then to remedy the same by replacing or cementing the packing,or by the use of expensive and complex machinery for larger diameterpipes to locate a given joint and internally apply cement thereto. Ineither event, the process was not only uncertain and costly but requiredthe gas main to be out of use for a relatively long time.' Moreover, at-

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tempts to restore the swollen state of the fibrous packing have hadfugitive results, due to drying or leaching of the material used.

I have discovered that by the use of a new process involved in myinvention, it is possible to seal a conduit or vessel, whether of thegas main type or otherwise, and whether it incorporates a jute or otherfiber packing or otherwise, without removing the paving or digging, orusing expensive or complex machinery. Moreover, it is accomplished in aminimum of time and with a maximum assurance that the leak will bereadily found and cornpletely sealed, the sealing being dependable andsubstantially permanent, and without adversely affecting the fiow ornature of the fluid carried o r held by said conduit or vessel. Not onlyso, but my invention makes it possible to seal actual fissures in theconduit or vessel, which formerly would require patching, caulking oractual replacement.

In the practice of my invention, I employ a sealant which is pumped orotherwise introduced into the interior of the conduit or vessel while ina liquid state until the receptacle is as nearly full as possible. By acombination of capillary action, hydrostatic pressure, and ionicattraction, the sealant flows into and penetrates the fissure or joint,filling the spaces therein and particularly filling the intersticesbetween the adjacent fibers of the packing and between the packing andthe walls or caulking of the joint, and substantially wetting said Wallsor caulking in the process. The excess liquid sealant is then pumped orotherwise drawn out of said interior, leaving a thin film of saidsealant deposited against the walls and packing.

The sealant is of such a nature as not only to penetrate the intersticesbetween adjacent fibers, but also to deposit a filler therein while atthe same time embracing said fibers in such a manner as to utilize thefibers as fillers; and then on drying after the withdrawal of saidexcess from the interior, to cure in a relatively short time, changingthe general physical characteristics from a liquid to an elastic, tough,and rubbery mass which itself packs the fissures, and cements the fiberstogether Iwhile anchoring the whole mass of fibers into the joint. Forthe purpose of illustrating my invention, I have shown in theaccompanying drawings forms thereof which are at present preferred byme, since the same have been found to give satisfactory and reliableresults, although it is to be understood that the variousinstrumentalities of which my invention consists can be variouslyarranged and organized, and that my invention is not limited to theprecise arrangements and organizations of the instrumentalities asherein shown and described.

Referring now to the drawings: FIGURE 1 represents a diagrammatic viewof a vessel j such as a gas main being internally sealed in accordancewith the process of my invention.

FIGURE 2 represents an enlarged sectional' view of the bell and spigotjoint illustrated in FIGURE 1 before the application of my processthereto.

FIGURE 3 represents a sectional view similar to FIG- URE 2, andillustrating one stage of my process, wherein the interior of the vesselis substantially filled with a sealant in accordance with my invention.

FIGURE 4 represents a sectional view similar to FIG- URE 2 andillustrating a subsequent stage of myprocess, in which all excessliquidk sealant has been evacuated, leaving a thin rubbery film adheringto the interior of the vessel and united to a tough, rubbery massreenforced by the fibers of the original packing, in accordance with myinvention.

FIGURE 5 represents a greatly enlarged view of a section of the bell andspigot joint illustrated in FIGURE 2, illustrating the penetration ofthe filamentous packing by means of ionic attraction, in accordance withthe process of my invention.

FIGURE 6 represents a section view similar to FIG- URE 5, illustratingthe coagulated sealant embracing the fibers of the penetrated packing,following the withdrawal of excess sealant from the vessel, inaccordance with my invention.

FIGURE 7 represents a greatly enlarged view of a section of a bell andspigot joint in which caulking was used in place of fiber, and in whichleakes were formed through the caulking and through a wall of thevessel, said joint having thereafter Ibeen sealed by means of theprocess of my invention.

FIGURE 8 represents a magnified View of sealant containing fiber-typefillers in accordance with my invention.

While my invention is adapted for use with substantially any type ofconduit, reservoir, vessel or container, any of which may hereafter lbereferred to as a Vessel, for purposes of illustration only, theaccompanying drawings illustrate a gas main having a bell and spigotjoint. Thus, the gas main may be referred to generally by the referencenumeral 10, and comprises a bell and spigot joint 11, a fitting 12 and acut-off valve 13. The fitting 12 is adapted to have connected therewitha suitable conduit 14 leading from a pump 15 which in turn is connectedto a reservoir 16 by any suitable means 17, operably to transfer thecontents of the reservoir into the interior of the gas main wherein saidcontents may remain under pressure, and then to withdraw the excesscontents from said gas main and back into the reservoir 16.

The bell and spigot joint 11 comprises the spigot 18 having an end edge19 and an end exterior wall region 20 inserted within the bell 21 havingan interior wall region 22 and an interior seat portion 23. Filamentouspacking such for instance as jute 24 may be disposed between the spigot18 and the bell 21 in a manner to be tightly packed between the exteriorwall region 20 of the spigot 18 and the interior wall 22 of the bell 21,and between the end edge 19 of the spigot 18 and the seal portion 23 ofthe bell 21. Additional caulking such for instance as lead or othersuitable material 25 may -be disposed between the spigot 18 and bell 21and exterior of the filamentous packing 24.

When it is desired to seal this joint in accordance with the process ofmy invention, the conduit 14 may be fitted to the gas main 20, and ifdesired the cut-off valve 13 may be closed. A sealant 26 of a typepreferably comprising a liquid dispersion of elastomeric rubbery solids,a stabilizing agent, a curing agent, a low temperature cure acceleratorand reenforcing material, and which may bear a cationic charge, may ybecarried in the reservoir 1-6 and may then be led out of said reservoirand into the interior of the gas main 10 by means of the pump until theinterior of the gas main 10 is substantially full, as illustrated inFIGURE 3. The sealant 26 then penetrates the interstices between thefilaments in the packing 24, and all fissures wherever said sealantcomes in contact with them. This is accomplished not merely by thepressure of the liquid sealant 26 within the vessel 10 tending toforceitself through said interstices and fissures, or the normal capillaryattraction between the surfaces surrounding said openings and saidliquid, but also by the ionic attraction between opposite charges. Thus,in the case of the jute 24 which normally has a negative ionic charge asillustrated by the negative symbols 27 in FIGURE 5, the cationic sealant26, whose positive charge is illustrated by the plus symbols 28, isdrawn through the interstices 29 ybetween the jute fibers 30 by saidionic attraction between the opposite charges.

The thus established penetration is of such a nature as not only to fillthe interstices between the fibers, but to fill the region 31 adjacentthe interior 32 of the gas 4 main 10 and between `the end edge 19 of thespigot 18 and the seal portion 23 of the bell 21, operably to emlbracethe fibers within the sealant 26 in said region 31.

The excess liquid sealant 26 is then pumped out of the gas main 10 as bymeans of the pump 15, and `back into the reservoir 16 for re-use forsealing other vessels; and for the purpose of this pumping operation,suitable venting may be used such as opening the cut-off valve 13. Aresidue of the sealant 26 will however have the wet interior 32 of thegas main 10 operably to coat the same; and the combination of ionic andcapillary attraction between the sealant and the fibers 30 is so muchgreater than the withdrawing action of the pump 15, that virtually nosealant is lost from the region 31. The conduit 14 may then be removedfrom the fitting 12, the cutoff valve 13 is fully opened, and the gasmain 10 allowed to resume its normal operation of conveying gas. Theflow of gas therethrough tends to aspirate moisture from the sealantwhich has wet the interior 32 of the main 10, and from the sealant inthe region 31, operably to dry the same. As drying takes place, thelatex in the sealant coagulates andcures to form a tough, rubbery mass33 reenforced by jute fibers in the region 31, and a thin rubbery film34 coating the interior 32 of the gas main 10 operably further toprotect it from leaks which could possibly form through fissures whichhad not yet penetrated the interior.

In FIGURE 7 is illustrated the operation of the procv ess of myinvention in sealing leaks which are not associated with fibrouspacking. Thus, a caulking 35 such for instance as a metallic typecaulking may be disposed between the bell 21 and spigot 18. Should afissure 36 have formed through the caulking 35, or a fissure 37 haveformed through the wall of the gas main 10, the process of my inventioncan `be used permanently to remedy the same. Thus, the sealant 26 may beintroduced to the gas rnain 10 by means of the reservoir 16 and pump 15as heretofore described until the interior is substantially full ofsealant. The pressure of the liquid within the main 10 tends to forcethe liquid sealant through the fissures 36 and 37, and this penetratingaction is further enhanced by capillary attraction. When the sealant isthen removed from the interior of the gas main 10, as by means of thepump 15, the entire interior will have -been wet 'by the sealant 26operably to leave a coating thereon. As this coating dries, whether byfiow of gas through the main or by normal drying action, the latex inthe sealant coating the interior coagulates leaving a film 38 throughoutthe interior and joining the latex plugs 39 in the fissures 36, 37.These latex plugs consist of a tough, rubbery mass. In the case ofsealant which comprises a reenforcing agent consisting of filamentousmaterials 40 for instance as illustrated in magnified form in FIGURE 8,the filamentous materials themselves lend considerable strength to themass. Moreover, the adhesive attraction of the latex to the filamentssupplements the cohesive strength of the latex operably greatly toincrease the strength of the plug 39 and to resist any physiycal forcesuch for instance as street vibration which could possibly tendadversely to affect the seal. However, my invention is not limited to asealant reinforced by filamentous particles, but contemplates the use ofany sealant as defined in the claims.

I have found that such a sealant which has proven satisfactory for thispurpose can be made by suspending in water a curing agent, curingaccelerator, filler, re-enforcing agent and anti-oxidant, and combiningthe same with an aqueous solution of dispersing agent, colloidstabilizer and an aqueous dispersion of stabilized latex. This may bedone in many different ways, and the following examples are to be takenas illustrative of ways which have proven practical:

EXAMPLE 1 The following ingredients were charged into an 18" diameter x18 long pebble mill half filled with int pebbles ranging downward insize from approximately YA" diameter.

After grinding for 2A hours with the mill rotating at 30revolutions/minute, the charge was removed from the mill and added tocationic polychloroprene latex as follows: 73 pounds of cationicpolychloroprene latex containing approximately '50% polychloroprene byweight was placed in an agitated vessel, the agitation energy beingequivalent to 0.5 horsepower/ l100 gallons. Tert-dodecyl lthioether as a25% water solution was added in a quantity of 0.10 pound. A aqueoussolution of polyfvinyl alcohol was added in an amount of 4.5 pounds,both of these stabilizers being added with the agitator running. Afterthe stabilizers were added to the latex and with the agitator stillrunning, the dispersed solids fromthe ball mill were added to the latexat a uniform rate over a period of 5 minutes. After all of the dispersedsolids were added to the latex, agitation was continued for another 5minutes.

EXAMPLE 2 The following ingredients were charged into an 18" diameter x18" long pebble mill half filled with flint pebbles ranging downward insize from approximately 5X1 diameter.

After grinding for 24 hours with the mill rotating at 30revolutions/minute, the charge was removed from the mill end added toanionic polychloroprene latex as follows:

73 pounds of anionic polychloroprene latex containing 50%(approximately) polychloroprene by weight was placed in an agitatedvessel, the agitation energy being equivalent to 0.5 horsepower/ 100gallons. Tert-dodecyl thioether as a 25% water solution was added in aquantity of 0.10 pound. A 10% aqueous solution of polyvinyl alcohol wasadded in an amount equal to 4.5 pounds. Both of these stabilizers wereadded with the agitator running. After the stabilizers were added to thelatex, and with the agitator still running, the dispersed solids fromthe ball mill were. added to the latex at a uniform rate over a periodof 5 minutes. After all ofthe dispersed solids were added to the latex,agitation was continued for another 5 minutes to assure uniformity ofmixing.

EXAMPLE 3 Same as Example 2 excepting latex used was a copolymer ofbutadiene and styrene.

EXAMPLE 4 Same as Example 2, excepting latex used was a ycopolymer ofbutadiene and acrylonitrile.

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6 EXAMPLE 5 Same as Example 2, excepting that an ammonia free naturalrubber latex was used. This was prepared from a `commercially availablenatural rubber latex by adding a 3% aqueous Isolution of potassiumhydroxide at the rate of one pound per 25 pounds of 50% natural rubberlatex and blowing nitrogen gas through the latex at a rate of 0.1 cubicfoot/minute for 8 hours to remove the ammonia gas.

The foregoing examples are intended to illustrate and should not beinferred to limit. Inded, any elastomeric latex may be used, care beingtaken to provide a cationic latex in the combination indicated forExample 1, and anionic latex for the combinations indicated in Examples2 to 5 inclusive.

Thus, also the zinc oxide can be replaced by another curing agent. Suchagents which I have found will promote an effective cure includemagnesium oxide, and lead oxide;` although I have found that zinc oxideis preferable.

The thiocarbanilide is one of several satisfactory low temperature cureaccelerators. Another one which I have found satisfactory isthiuramdisulde.

The phenyl beta naphthylamine can be replaced by phenyl alphanaphthylamine or by any other suitable antioxidant.

The sodium hydroxide can be replaced by lithium hydroxide or potassiumhydroxide.

The tert-dodecyl thioether can be replaced by any water solublenon-ionic surface active agent.

'The sodium salt of lignin sulfonic acid can be replaced by any suitableanionic water soluble surface active agent, such for instance as eitherof the agents which may be obtained commercially under the trademarkEmulphor- O-N or Aerosol-O-T, said Emulphor-O-N being composed ofpolythylene either -stearate, and said Aerosol-O-T lbeing composed ofdioctyl sodium sulfosuccinate.

The polyvinyl alcohol can be replaced by any suitable solublestabilizing agent for the latex.

The carbon black can be replaced by any of a large number of othersuitable reinforcing agents, such for instance as clays, Whiting,selected pigments, and-fibers. An effective reinforcing agent was foundto be fiber glass of a length between 1/16 and 1A", introduced at thefinal agitation stage in place of the milling stage, and preferably ofthe same specific gravity as that of liquid in which it was introduced.In the case of fiber-type fillers, it was found that the ultimatelycured seal was considerably toughened and strengthened by virtue ofreducing the distance between anchor locations of the elastomer. Theelastomer was thus shortened from anchor location to anchor location,even though the space to be filled by the sealant may have beensubstantially large. In this way, large fissures and indeed substantialopenings in conduits were effectively sealed.

Moreover, for certain purposes a satisfactory sealant was made accordingto the foregoing examples with less than all the ingredients, or theirreplacements, specified therein. Thus, it was found that the reinforcingagent such as carbon black or its replacements, the sulphur, the curingaccelerator such as the thiocarbanilide or its replacements, antioxidantsuch as the phenyl beta naphthylamine or its replacement, the latexstabilizer such as the poly` vinyl alcohol, and in some instances thelong chain fatty acid amide, could variously, severally or all bedeleted without preventing a sealant from being made which would besatisfactory for certain purposes. However each of these ingredientscontributes substantially to the sealant which I have found mostdesirable.

Also, in place of milling, other known means of homogenization may beused. l

It has also been found that variations may be used in the proportions ofingredients, and still produce a sealant which may be satisfactory forgiven purposes. For instance, referring to the amounts of milledingredients specified in Examples 1 and 2, the zinc oxide may be used inamounts between 2 pounds and 12 pounds, the sodium hydroxide may be usedin amounts between .04 pound and .50 pound, the tert-dodecyl thioethermay be used in amounts between .10 pound and 1.00 pound. The ethyleneoxide-rosin amine adduct may be used in amounts ibetween 3.0 pounds and10.0 pounds, and the long chain fatty acid amide may be used in amountsbetween .25 pound and 3.00 pounds. The sodium salt of lignin sulfonicacid may be used in amounts between .06 pound and 1.00 pound. And in thelatex composition as described prior to the introduction of the milledingredients, the tert-dodecyl thioether may be used in amounts between.06 pound and 1.0 pound. Also the polyvinyl alcohol may be used inamounts up to 13.5 pounds.

The percentage of water may also be varied. Thus, I have found that mysealant will work satisfactorily for various purposes when the solidcontent thereof is between 5% and 55%. Above 55% instability may occur.Below 30% there is a substantial reduction in the rate of penetrationand deposition.

I also found that, particularly when the packing required to be sealedconsists of jute or other organic fiber, that modification of my sealantwhich includes cationic latex penetrates much more quickly andeffectively, the positively charged latex having a marked attraction forthe negatively charged organic fibers, not only increasing the speed ofpenetration, but also substantially increasing the strength of the seal.Not only so, but the ethylene oxide-rosin amine adduct and the longchain fatty acid amide, are corrosion inhibitors which would furthercontribute to the protection of the conduit or vessel being sealed.

Moreover, the sealant of my invention is non-toxic, non-volatile,non-explosive, non-flammable when in liquid form, and non-ammable whenin coagulated form when the latex is polychloroprene, and inert in thepresence of aliphatic hydrocarbons such for instance as illuminatinggas, and may be introduced into a conduit and withdrawn therefrom asdescribed hereinabove without coagulation, so that the thus withdrawnsealant can be used again and again in the same manner. Not only so,lbut when thus introduced and withdrawn it not only penetrates and sealsthe joints, fibers and fissures, but it also leaves a thin film aboutthe interior of the conduit or vessel, which coagulates and cures into apermanent seal against future fissures that may form in the conduit orvessel structure. This film, in the case of the product of Examples 1and 2, may have a thickness of .002 inch to .003 inch. Also, thepenetrated fissures, fibers, openings and joints are very substantiallystrengthened by the resultant coagulated and cured sealant, particularlywhen a reinforcing agent is contained therein.

The term vessel, used in the title and the claims, is intended toinclude conduits, reservoirs, vessels or con-v tainers which are treatedby the method of this invention.

I am aware that the invention may be embodied in other specific formswithout departing from the spirit or essential attributes thereof, and Itherefore desire the present embodiment to #be considered in allrespects as illustrative and not restrictive.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A gas-tight vessel comprising an interior wall, an exterior wall, andan interstice therebetween, a coagulated and cured, cationic, neoprenelatex sealant coating adhering to said interior wall in the vicinity ofsaid interstice, and plugging said interstice against gas leakage, saidcoagulated latex coating composition being the coagulated and curedproduct of the aqueous dispersion of a cationic neoprene latex, acationic surface active agent, a non-ionic surface active agent, of atotal solids content in the range of about 5 to about 55% by weight, thecationic surface active agent being in an amount in the range of about 80.5 to about 6% by weight, the non-ionic surface active agent in anamount less than the cationic surface active agent and in the range ofabout 1.2 to about 5% by weight, said dispersion having an ionic chargeopposite `to that of the ionic charge of the walls defining theinterstice and being stable and non-coagulating prior to and afterwithdrawal from and after having coated the interior of said vessel.

2. The vessel of claim 1 further comprising a jute packing disposed insaid interstice, the fibers of said jute packing being embraced withinand reenforcing said coagulated latex coating composition against gasleakage.

3. The vessel of claim 1 which defines a multiplicity of fissures whichare sealed against gas leakage by the latex sealant composition.

4. The vessel of claim 1 in which the sealant further comprises a curingagent and a low temperature cure accelerator.

5. The gas-tight joint of claim 1 further comprising a caulking.

6. The joint of claim 5 in which the caulkng is metallic.

7. The gas-tight vessel of claim 1 which is a gas main.

8. The gas-tight vessel of claim 3 in which a coating of the sealantcomposition on the interior of the vessel connects the sealed fissures.

9. The gas-tight vessel of claim 1 further comprising a filamentousreenforcing agent distributed in the sealant composition in theinterstice.

10. The gas-tight vessel of claim 1 further comprising carbon black,distributed in the sealant composition in the interstice.

11. The gas-tight vessel of claim 1 in which the sealant composition iscured without application of heat.

12. The vessel of claim 1 in which the coating is selected from one ofthe following copolymers of butadiene and styrene and butadiene andacrylonitrile.

13. The vessel of claim 3 in which the coating further comprises fiberglass.

14. The vessel of claim 3 in which the coating further comprisespolyvinyl alcohol. 15. A gas-tight vessel comprising an interior wall,an exterior wall, and an interstice therebetween, a coagulated andcured, anionic, neoprene latex sealant coating adhering to said interiorwall in the vicinity of said interstice, and plugging said intersticeagainst gas leakage, said coagulated latex coating composition being thecoagulated and cured product of the aqueous dispersion of an anionicneoprene latex, an anionic surface active agent, a non-ionic surfaceactive agent, of a total solids content in the range of about 5 to about55% by weight, the anionic surface active agent being in an amount inthe range of about 0.5 to about 6% by weight, the non-ionic surfaceactive agent in an amount less than the anionic surface active agent andin the range of about 1.2 to about 5% by weight, said dispersion havingan ionic charge opposite to that of the ionic charge of the wallsdefining the interstice and being stable and non-coagulating prior toand after withdrawal from and after having coated the interior of saidvessel.

References Cited UNITED STATES PATENTS 2,094,691 10/1937 Williams285-295 X 2,791,567 5/1957 Lowe et al. 260-611 X 2,837,122 6/1958 Shawet al. 106-33 X 2,885,299 5/1959 Labino 117-2 v2,912,350 11/1959 Videenet al. 26o-29.7 X 2,995,512 8/1961 Weidner et al 117-163 X 2,851,0619/1958 Bernard et al. 138-97 DAVID J. WILLIAMOWSKY, Primary Examiner D.W. AROLA, Assistant Examiner

